System, Method, and Apparatus for Detecting Coupling to a Patient Using One or More Electric-Field Sensors

ABSTRACT

A pump for infusing fluid, the pump including a pumping mechanism, a fluid delivery device, a plurality of electric field sensors, and a measurement component. The plurality of electric field sensors is configured to estimate either an electric field that is associated with a patient, or an electric field that is associated with a fluid path of the pump, or both. The measurement component is configured to receive the electric field estimates from each of the electric field sensors and further configured to measure the difference between the electric field estimates.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a Non-Provisional Application which claimsthe benefit of U.S. Provisional Patent Application Ser. No. 61/987,742,filed May 2, 2014 and entitled System, Method, and Apparatus forDetecting Coupling to a Patient Using One or More Electric-Field Sensors(Attorney Docket No. K51), which is hereby incorporated herein byreference in its entirety.

BACKGROUND

1. Relevant Field

The present disclosure relates to detecting whether an apparatus iscoupled to a patient. More particularly, the present disclosure relatesto a system, method, and apparatus for detecting whether an apparatus,for example an infusion pump or a dialysis machine, is coupled to apatient using one or more electric-field sensors.

2. Description of Related Art

Using a pump to infuse fluid into a patient generally requires tubingand a fluid delivery device (e.g., catheter, cannula, IV, etc.) be usedto infuse the fluid into the patient. Despite the best efforts ofprofessionals and caregivers (e.g., doctors, nurses, technicians, nursepractitioners, etc.), the tube through which the fluid is being infusedmay inadvertently become disconnected from the patient. The pump maycontinue to pump the fluids even though the patient is no longerconnected, which, not only wastes fluid, but prevents the patient fromreceiving the much needed fluid. In the case of a hemodialysis pump,either the tube being used to pump blood from the patient, the tubebeing used to pump blood back into the patient, or both tubes mayinadvertently become disconnected from the patient.

SUMMARY

A pump for infusing fluid, said pump comprising a pumping mechanismconfigured to pump fluid, a first electric field sensor configured toestimate a first electric field associated with a patient, a secondelectric field sensor configured to estimate a second electric fieldassociated with said patient, wherein said first and second electricfield sensors are configured to be operatively coupled to a fluid pathof said pumping mechanism, and a measurement component configured tomeasure differences between said first electric field and said secondelectric field.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects will become more apparent from the followingdetailed description of the various embodiments of the presentdisclosure with reference to the drawings wherein:

FIG. 1 is a block diagram of a system having a pump that utilizes twoelectric fields sensors to determine if the pump is coupled to a patientin accordance with an embodiment of the present disclosure;

FIG. 2 is a block diagram of a system for processing an electric-fieldsensor in accordance with an embodiment of the present disclosure;

FIG. 3 is a block diagram of a system for detecting a heartbeat ofpatient using two electric-field sensors in accordance with anembodiment of the present disclosure;

FIG. 4 is a block diagram of a system having a pump that has twoelectric-field sensors wherein one of the electric field sensors iscoupled to a patient through a wristband and the other one of theelectric-field sensors is part of a fluid delivery device to inaccordance with an embodiment of the present disclosure;

FIG. 5 is a block diagram of a system having a pump that has twoelectric-field sensors wherein one of the electric field sensors iscoupled to a patient through a wristband and the other one of theelectric-field sensors is coupled to a fluid path of a fluid deliverydevice in accordance with an embodiment of the present disclosure;

FIG. 6 is a block diagram of a system having a pump that is coupled toan IV bag with an electric-field sensor for infusing fluid into apatient and a wristband with another electric-field sensor coupled tothe patient in accordance with an embodiment of the present disclosure;

FIG. 7 is a block diagram of a circuit for muscle activity detection inaccordance with an embodiment of the present disclosure;

FIG. 8 is a block diagram of an apparatus for muscle activity detectionin accordance with an embodiment of the present disclosure;

FIG. 9 is a block diagram of a system having a pump with anauthentication circuit in accordance with an embodiment of the presentdisclosure;

FIG. 10 is a block diagram of an authentication circuit in accordancewith an embodiment of the present disclosure;

FIG. 11 is a flowchart diagram illustrating a method for detectingwhether a patient is in the fluid path of the pump in accordance with anembodiment of the present disclosure; and

FIG. 12 is a flowchart diagram illustrating a method for authenticatinga command for the pump in accordance with an embodiment of the presentdisclosure.

DETAILED DESCRIPTION

In some embodiments, a pump as described herein refers to an infusionpump; however, other pumps may be used in various embodiments of thepresent disclosure, such as insulin pumps, dialysis pumps, etc. Thepumps may utilize one or more electric-field sensors as describedherein.

FIG. 1 is a block diagram of a system 100 having a pump 101 thatutilizes two electric-field sensors 108, 110 to determine if the pump101 is coupled to a patient 106 in accordance with an embodiment of thepresent disclosure.

Referring to FIG. 1, a generalized view of a pump 101 is shown. The pump101 is shown to include a pumping mechanism 102, two electric fieldsensors 108, 110 each configured to estimate an electric field, and ameasurement component or circuit 112. A fluid delivery device 104 (e.g.,catheter, cannula, IV, etc.) and a patient 106 are shown in the fluidpath of the pump. The fluid path of the pump includes connections 114and 103. The fluid path may also contain connection 118 if necessary toperform the treatment of the patient 106. Connections 116 and 124 showelectric field sensors 108 and 110 estimating an electric field fromboth the fluid delivery device 104 and the patient 106, respectively.

In some embodiments, the electric field sensors 108 and 110 areconfigured to estimate either the magnitude of an electric field, or theflux of an electric field, or both. In some embodiments, the estimatedelectric field may be an electric field associated with a muscle of thepatient 106, or, further, in some embodiments, the estimated electricfield may be generated by electrical activity associated with the heartof the patient 106. In yet further embodiments, the estimated electricfield may be associated with other biological electrical activitypertaining to other organs or tissue. Connections 122 and 126 showelectric field sensors 108 and 110 respectively communicating theestimated electric field to the measurement component 112. Themeasurement component 112 may use the input received from the electricfield sensors 108 and 110 through connections 122 and 126, respectively,to determine a heartbeat of the patient 106. The connections 116, 124,122 and 126 may be wired connections, wireless connections, or acombination thereof, in some embodiments.

In some embodiments, the electric field sensor 108 may be on or near anypart of the fluid path including, but not limited to, on or near thetubing, on or near the fluid delivery device 104, and on or near thepumping mechanism 102. In some embodiments, the measurement component112 may be outside of the pumping mechanism 102. In some embodiments, ifone of the electric field sensors 108 or 110 stopped communicating theestimated electric field, then the measurement component 112 may not beable to determine the heartbeat of the patient 106. One of the electricfield sensors 108 or 110 may stop communicating its respective estimatedelectric field if the sensor was no longer able to estimate the electricfield. The electric field sensor 108 may not be able to estimate theelectric field if, for example, the fluid delivery device 104 becamedetached from the patient 106.

FIG. 2 is a graphical representation of a heartbeat detection circuit,part or all of the heartbeat detection circuit being included in themeasurement component 112 of FIG. 1, in some embodiments. In someembodiments, the heartbeat detection circuit will receive input from theelectric field sensor 202. The heartbeat detection circuit may alsoinclude a first signal filter 204, a second signal filter 206, a signalamplifier 208, a first buffer amplifier 210, and a second bufferamplifier 212. In some embodiments, the first signal filter 204 mayallow signals with a frequency below a desired threshold to pass throughthe filter, while the filter attenuates the amplitude of any signalswith a frequency greater than the desired threshold. The first signalfilter 204 may be a low pass filter, and, in yet further embodiments,the low pass filter may have a cutoff threshold of 40 Hertz (Hz). Thesecond signal filter 206 may allow signals with a frequency below orabove a certain threshold pass through the filter, yet the filter mayattenuate the amplitude of signals whose frequency matches the thresholdfrequency. In some embodiments, the second signal filter 206 is a bandstop filter, while, in yet further embodiments, the second signal filtermay be a 60 Hz notch filter, the filter attenuating signals having afrequency of 60 Hz. In some embodiments, the 60 Hz notch filter may beused to attenuate ambient noise. The signal amplifier 208 may be avariable gain amplifier. The variable gain amplifier 208 may utilize thepower supply 214 in order to increase the amplitude of the signal comingfrom the second signal filter 206. The variable gain amplifier 208 maythen output the signal to the two buffer amplifiers 210, 212. In someembodiments, the two buffer amplifiers are voltage buffer amplifiers. Inyet other embodiments, the voltage buffer amplifiers may have a voltagegain of 1, or, in other words, be voltage followers. In someembodiments, although the buffer amplifiers 210, 212 may have a voltagegain of 1, they may have a larger gain as required.

FIG. 3 is a graphical representation of two heartbeat detection channels302, 304 and a measurement component 306. Each heartbeat detectionchannel may each include a heartbeat detection circuit as depicted inFIG. 2. The first heartbeat detection channel 302 may receive an inputsignal from the electrical field sensor 108, and may send an outputsignal to the measurement component 306. Similarly, the second heartbeatdetection channel 304 may receive an input signal from the electricalfield sensor 110, and may send an output signal to the measurementcomponent 306. The measurement component 306 may use the output signalsof the first and second heartbeat detection channels 302, 304 todetermine a heartbeat of a patient (e.g., the patient 106 of FIG. 1). Insome embodiments the measurement component 306 may be a differentialamplifier. The measurement component 306 may include an automatic gaincontrol function.

Referring now to FIGS. 4-6, various embodiments are shown wherein thepatient is wearing a wristband with an electric field sensor. Referringto FIG. 4, the patient may wear a wristband with an electric fieldsensor 404, and a second electric field sensor may be located on thefluid delivery device 402 in the fluid path of the pump 400. The fluiddelivery device 402 may be a catheter, an IV bag, or other fluiddelivery device, the second electric field sensor configured to estimatean electric field associated with the fluid delivery device 402.Similarly, the wristband with the electric field sensor 404 may beconfigured to estimate an electric field associated with the patient106. Both the wristband with the electric field sensor 404 and the fluiddelivery device with the second electric field sensor 402 may providetheir respective electric field estimate to the measurement component112, the measurement component 112 being part of the pumping mechanism102 in some embodiments.

Referring to FIG. 5, the patient may wear a wristband with an electricfield sensor 504, and a second electric field sensor 506 may be on ornear the tubing in the fluid path of the pump 500. Similar to thewristband in FIG. 4, the wristband with the electric field sensor 504 inFIG. 5 may be configured to estimate an electric field associated withthe patient 106. The wristband 504 may be further configured tocommunicate the estimate of the electric field to the measurementcomponent 112. In some embodiments, the second electric field sensor 506may be on or near the tubing near the fluid delivery device 104. Thesecond electric field sensor 506 may be configured to estimate anelectric field associated with the fluid path near the fluid deliverydevice 104. The second electric field sensor 506 may be furtherconfigured to communicate the estimate of the electric field to themeasurement component 112.

Referring now to FIG. 6, in some embodiments, the pump 600 may include awristband with an electric field sensor 604 that may be worn by thepatient 106, and the pump 600 may further include an IV bag 602 with asecond electric field sensor coupled thereto. The IV bag 602 may be inthe fluid path of the pump 600 via fluid connection 606 between the IVbag 602 and the pumping mechanism 102, and via fluid connection 608between the pumping mechanism 102 and the patient 106. Similar to theabove mentioned embodiments, the electric field sensor on the IV Bag 602may estimate an electric field associated with the fluid path of thepump 600 and communicate the estimate of the electric field to themeasurement component 112. Similarly, the electric field sensor on thewristband 604 may estimate an electric field associated with the patient106 and communicate the estimate of the electric field to themeasurement component 112. The measurement component 112, as mentionedabove, may use the input from each electric field sensor to determine aheartbeat associated with the patient 106.

FIG. 7 is a graphical representation of a muscle stimulation detectioncircuit 700. The muscle stimulation detection circuit 700 may include afirst electric field sensor 702, a second electric field sensor 714,each of the first and second electric field sensors 702, 714 beingoperably connected to at least one signal filter and at least one signalamplifier. The first electric field sensor 702 and the second electricfield sensor 714 may be configured to estimate an electric fieldassociated with a first muscle portion and a second muscle portion,respectively. The first muscle portion, in some embodiments, may be neara first muscle extreme, while, similarly, the second muscle portion maybe near a second muscle extreme. The first and second electric fieldsensors 702, 714 may each communicate their respective electric fieldestimates to a measurement component 724.

In some embodiments, the electric field estimates may be included inrespective first and second output signals from the first and secondelectric field sensors 702, 714. The first output signal may becommunicated from the first electric field sensor 702 to the measurementcomponent 724 via the at least one signal filter and the at least onesignal amplifier operably connected to the first electric field sensor702. Similarly, the second output signal may be communicated from thesecond electric field sensor 714 to the measurement component 724 viathe at least one signal filter and the at least one signal amplifieroperably connected to the second electric field sensor 714. In someembodiments, the muscle stimulation detection circuit 700 may furtherinclude a power supply 712. The power supply 712 may be configured toallow each at least one signal amplifier to increase the amplitude ofthe output signal from the signal amplifier's respective electric fieldsensor. The measurement component 724 may be configured to determine adifference in electric field magnitude between the first muscle portionand the second muscle portion. In some embodiments, the measurementcomponent 724 may be configured to determine a difference in electricfield flux between the first muscle portion and the second muscleportion.

In some embodiments, the at least one signal filter and at least onesignal amplifier for each electric field sensor, 702, 714, as well asthe measurement component 724 may be contained in an electronics box 808as depicted in FIG. 8. In some embodiments, the power supply 712 mayalso be included in the electronics box 808. FIG. 8 is a graphicalrepresentation of a muscle stimulation detection circuit, such as thestimulation detection circuit 700 of FIG. 7. The muscle stimulationdetection circuit of FIG. 8 may include, in addition to the electronicsbox 808, a first electric field sensor 804 and a second electric fieldsensor 806. The first and second electric field sensors 804, 806 beingoperably engaged with a first portion and a second portion of a muscle802, respectively. In some embodiments, the first and second electricfield sensors 804 and 806 may be the first and second electric fieldsensors 702 and 714 of FIG. 7, respectively.

Referring now to FIG. 9, a generalized view of a pump 900 with anauthentication circuit is shown. In some embodiments, the authenticationcircuit may be used to identify a patient, a pump operator, or anotherperson. The pump 900 is shown to include a pumping mechanism 902, whichmay include a modulator 912, an electric field sensor 908, and acommunication unit 910 in communication with the modulator 912. In someembodiments, the modulator 912 may be located outside of the pumpingmechanism 902. A fluid delivery device 904 (e.g., catheter, cannula, IV,etc.) and a patient 906 are shown in the fluid path of the pump. Thefluid path of the pump includes connections 914 and 916. The fluid pathmay also contain connection 918 if necessary to perform the treatment ofthe patient. The modulator 912 may be operatively coupled to the patient906, or the fluid path of the pump 900. As such, the modulator 912 maybe configured to apply a modulated electric field to the patient 906, orto the fluid path of the pump 900. In some embodiments, the modulator912 or the electric field sensor 908 may be operatively coupled to thepatient 906 via another fluid path. Similarly, the electric field sensor908 may be operatively coupled to the fluid path of the pump 900, or thepatient 906, and, as such, the electric field sensor 908 may beconfigured to estimate an electric field associated with the patient906, or with the fluid path of the pump 900, respectively. Theconnection 920 of FIG. 9 illustrates the electric field sensor 908estimating an electric field from the patient 906. Connections 922 and924 show communication unit 910 receiving the estimated electric fieldfrom electric field sensor 908 and communicating the estimated electricfield to the modulator 912.

The connections 920, 922 and 924 may be wired connections, wirelessconnections, or in some embodiments, a combination thereof. Themodulator 912 may be configured to provide a modulated electric field tothe fluid path of the pumping mechanism 902. In some embodiments, themodulator 912 may be configured to apply a modulated electric field tothe patient 906. In some embodiments, the modulator 912 may beconfigured to inject a signal into the patient 906, the communicationunit 910 being configured to recover the signal and subsequentlycommunicate the signal back to the modulator 912. In some embodiments,the signal may comprise a number. The communication unit 910 may also beconfigured to communicate at least one command to the modulator 912. Insome embodiments, the communication unit 910 may be configured tocommunicate an alert to the modulator 912 if the communication unit 910does not recover the signal from the modulator 912. The modulator 912may be further configured to output an error condition if the modulator912 does not receive the recovered signal from the communication unit910, or if the communication unit 910 communicates an alert to themodulator 912.

In some embodiments, the communication unit 910 may also communicate acommand for the pump 900. In some embodiments, electric field sensor 908may be on or near any part of the fluid path including, but not limitedto, on or near the tubing, on or near the fluid delivery device, on ornear the pumping mechanism, and on or near the patient. In someembodiments, the communication unit 910 may be located within thepumping mechanism 902.

FIG. 10 is a graphical representation of how an authentication circuitrymay work to provide a secure system for giving commands to a medicalpump. The authentication circuitry may comprise a pump 1002 and acommunication unit 1018 operably connected to the pump 1002. Thecommunication unit 1018 may be operably connected to the pump 1002 byway of an electrical signal pathway as depicted in FIG. 10. Theelectrical signal pathway may include transmission of an electricalsignal through a medium. In some embodiments, the medium may include thebody of a person, or, further, the medium may include the body of apatient. In some embodiments, the pump 1002 may be the pumping mechanism902 as depicted in FIG. 9, and the communication unit 1018 may be thecommunication unit 910 as also depicted in FIG. 9. The pump 1002 mayinclude a source of binary control such as a microprocessor, avoltage-to-frequency converter 1004 and a drive component 1006. Thevoltage-to-frequency converter 1004 may be used to convert the digitalbinary control from a microprocessor within the pump 1002 to an analogsignal. The drive component 1006 may take the analog signal from thevoltage-to-frequency converter 1004 and broadcast the signal through theelectrical signal pathway such that the analog signal can be received bythe communication unit 1018. The analog signal from the drive component1006 may be detected by an electrical field sensor 1008, which, in someembodiments, may be part of the communication unit 1018, or, in otherembodiments, may be separate from the communication unit 1018. Further,in some embodiments, the electric field sensor 1008 may be the electricfield sensor 908 as depicted in FIG. 9.

The communication unit 1018 may comprise a first signal filter 1010 thatis configured to receive the detected analog signal from the electricfield sensor 1008, and a first peak detector circuit 1014 that isoperably connected to the signal filter 1010. The communication unit1018 may further include a second signal filter 1012 that is configuredto receive the detected analog signal from the electric field sensor1008, and a second peak detector circuit 1016 that is operably connectedto the signal filter 1012. The first and second signal filters, in someembodiments, may be band pass filters, each filter configured to allow adifferent range of frequencies to pass through.

In some embodiments, the first signal filter may be configured to allowa range of frequencies to pass through that is lower than the range offrequencies that the second signal filter is configured to allow to passthrough. Each of the first and second band pass filters may beconfigured to operably engage with the first and second peak detectorcircuits, respectively, to convert the detected analog signal into adigital binary signal. Each of the first and second peak circuitdetectors may output a digital signal to a microprocessor. Themicroprocessor may pass the digital signal from each of the first andsecond peak detector circuits through a threshold detector. In someembodiments the threshold detector may determine each time the digitalsignal from the first peak detector circuit crosses a lower threshold,and each time the digital signal from the second peak detector circuitcrosses an upper threshold. Each time the digital signal from the firstpeak detector circuit crosses the lower threshold, the microprocessormay identify that occurrence as representing a “0” in the digital binarysignal. Similarly, each time the digital signal from the second peakdetector circuit crosses the upper threshold, the microprocessor mayidentify that occurrence as representing a “1” in the digital binarysignal.

Referring now to FIG. 11, a method for detecting whether a patient is inthe fluid path of a medical pump is shown. At step 1102, a patient isconnected to the pump. Next, at step 1104, a first electric fieldassociated with a patient is measured from the fluid path of the pump;then, at step 1106, a second electric field associated with the patientis measured from the patient. In some embodiments, the first electricfield of step 1104 may be measured from the patient, and the secondelectric field of step 1106 may be measured from the fluid path. In someembodiments, the first electric field of step 1104 and the secondelectric field of step 1106 may be determined or measured by a firstelectric field sensor and a second electric field sensor, respectively.In step 1108, the differences between the first and second electricfield measurements are determined, and, in step 1110, those differencesare used to determine if the patient is still in the fluid path of thepump (i.e., the patient is still connected to the medical pump). In someembodiments, if the patient is still detected, the method may repeatsteps 1104-1110. In some embodiments, if the patient is not detected,the method may proceed to warning a healthcare professional that thepatient is not detected or shutting down the pump. In some embodiments,a healthcare professional may be warned in a variety of ways including,but not limited to, emitting an alarm, sending a message to a healthcareprofessional electronically (e.g., by phone, email, pager, etc.), anddialing an emergency number.

In some embodiments, the method may further include authenticating acommand for the medical pump, as referred to in FIG. 12. The method forauthenticating a command may include generating a random number in step1202, encoding the random number into a signal in step 1204, andbroadcasting the signal containing the random number into a patient instep 1206. In some embodiments, the broadcasting may occur through afluid delivery device. The method of FIG. 12 may further includedelivering the signal to a communication unit which may recover thesignal and the random number from the patient in step 1208, thecommunication unit communicating the recovered random number from therecovered signal to the medical pump in step 1210, and confirming thatthe communication unit communicated the random number in step 1212. Insome embodiments, the communication unit may communicate at least onecommand to the medical pump along with the recovered random number instep 1210. In further embodiments, the medical pump may output an errorcondition if the medical pump does not receive the random number fromthe communication unit. In some embodiments, the error condition may beoutput if the medical pump cannot confirm that the communication unitcommunicated the random number to the medical pump in step 1212.

Various alternative and modifications can be devised by those skilled inthe art without departing from the disclosure. Accordingly, the presentdisclosure is intended to embrace all such alternatives, modifications,and variances. Additionally, while several embodiments of the presentdisclosure have been shown in the drawings and/or discussed herein, itis not intended that the disclosure be limited thereto, as it isintended that the disclosure be as broad in scope as the art will allowand that the specification be read likewise. Therefore, the abovedescription should not be construed as limiting, but merely asexemplifications of particular embodiments. And, those skilled in theart will envision other modifications within the scope and spirit of theclaims appended hereto. Other elements, steps, methods, and techniquesthat are insubstantially different from those described above and/or inthe appended claims are also intended to be within the scope of thedisclosure.

The embodiments shown in the drawings are presented only to demonstratecertain examples of the disclosure. And, the drawings described are onlyillustrative and are non-limiting. In the drawings, for illustrativepurposes, the size of some of the elements may be exaggerated and notdrawn to a particular scale. Additionally, elements shown within thedrawings that have the same numbers may be identical elements or may besimilar elements, depending on the context.

Where the term “comprising” is used in the present description andclaims, it does not exclude other elements or steps. Where an indefiniteor definite article is used when referring to a singular noun, e.g.,“a,” “an,” or “the,” this includes a plural of that noun unlesssomething otherwise is specifically stated. Hence, the term “comprising”should not be interpreted as being restricted o the items listedthereafter; it does not exclude other elements or steps, and so thescope of the expression “a device comprising items A and B” should notbe limited to devices consisting only of components A and B. Thisexpression signifies that, with respect to the present disclosure, theonly relevant components of the device are A and B.

Furthermore, the terms “first,” “second,” “third,” and the like, whetherused in the description or in the claims, are provided fordistinguishing between similar elements and not necessarily fordescribing a sequential or chronological order. It is to be understoodthat the terms so used are interchangeable under appropriatecircumstances (unless clearly disclosed otherwise) and that theembodiments of the disclosure described herein are capable of operationin other sequences and/or arrangements than are described or illustratedherein.

What is claimed is:
 1. A pump for infusing fluid, said pump comprising:a pumping mechanism configured to pump fluid; a first electric fieldsensor configured to estimate a first electric field associated with apatient; a second electric field sensor configured to estimate a secondelectric field associated with said patient, wherein said first andsecond electric field sensors are configured to be operatively coupledto a fluid path of said pumping mechanism; and a measurement componentconfigured to measure differences between said first electric field andsaid second electric field.
 2. The pump of claim 1, wherein said firstelectric field and said second electric field are generated by saidpatient.
 3. The pump of claim 2, wherein said first electric fieldestimation and said second electric field estimation are estimations ofelectric-field magnitudes.
 4. The pump of claim 2, wherein said firstelectric field estimation and said second electric field estimation areestimations of electric flux.
 5. The pump of claim 2, wherein said firstelectric field and said second electric field are generated byelectrical activity associated with a heart of said patient.
 6. The pumpof claim 5, wherein said first electric field sensor is configured to becoupled to said patient, wherein said coupling is one of a wiredcoupling and a wireless coupling.
 7. The pump of claim 6, wherein saidsecond electric field sensor is configured to be coupled to a cannula insaid fluid path of said pumping mechanism.
 8. The pump of claim 6,wherein said second electric field sensor is configured to be coupled toa catheter in said fluid path of said pumping mechanism.
 9. The pump ofclaim 6, wherein said second electric field sensor is configured to becoupled to an intravenous bag in said fluid path of said pumpingmechanism.
 10. The pump of claim 6, wherein said second electric fieldsensor is configured to be coupled to a tube in said fluid path of saidpumping mechanism.
 11. The pump of claim 2, wherein said first electricfield and second electric field are generated by a muscle of saidpatient.
 12. The pump of claim 11, wherein said first electric fieldsensor is configured to be near a first extreme of a muscle of saidpatient and said second electric field sensor is configured to be near asecond extreme of said muscle of said patient.
 13. A pump for infusingfluid, said pump comprising: a pumping mechanism configured to pumpfluid; a modulator configured to provide a modulated electric field,wherein the modulator is configured to apply the modulated electricfield to at least one of a fluid path of said pumping mechanism and apatient; an electric-field sensor configured to estimate an electricfield associated with said patient, wherein said electric field sensoris configured to be operatively coupled to at least one of a fluid pathof said pumping mechanism and a patient; and a measurement componentoperatively coupled to the electric-field sensor to receive the estimateof the electric field.
 14. The pump of claim 13, further comprising acommunication unit in communication with said modulator.
 15. The pump ofclaim 14, wherein said communication between said communication unit andsaid modulator is a type of communication from the group consisting ofwireless communication and wired communication.
 16. The pump of claim13, wherein said modulator is configured to inject a signal with arandom number into said patient.
 17. The pump of claim 16, furthercomprising a communication unit in communication with said modulator,wherein said communication unit is configured to recover said randomnumber and communicate said random number.
 18. The pump according toclaim 17, wherein said communication unit is configured to communicateat least one command to said modulator.
 19. The pump of claim 17,wherein said communication unit is configured to communicate an alert tosaid modulator if said communication unit does not receive said randomnumber.
 20. The pump of claim 19, wherein said modulator is configuredto output an error condition if said modulator does not receive saidrandom number from said communication unit.
 21. The pump according toclaim 13, wherein said modulator is operatively coupled to said patientand said electric-field sensor is operatively coupled to said fluidpath.
 22. The pump according to claim 21, wherein said modulator isoperatively coupled to said patient via another fluid path.
 23. The pumpaccording to claim 13, wherein said modulator is operatively coupled tosaid fluid path and said electric-field sensor is operatively coupled tosaid patient.
 24. The pump according to claim 23, wherein saidelectric-field sensor is operatively coupled to said patient via anotherfluid path.
 25. A method for infusing fluid, said method comprising:connecting a patient to a medical pump; determining a first electricfield measurement associated with the patient; determining a secondelectric field measurement associated with the patient; measuring adifference between the first and second electric field measurements; andusing the difference to determine whether the patient is connected tothe medical pump.
 26. The method of claim 25, wherein the determining afirst electric field measurement is performed by a first electric fieldsensor and the determining a second electric field measurement isperformed by a second electric field sensor.
 27. The method of claim 26,further comprising authenticating a command for the medical pump. 28.The method of claim 26, further comprising providing a warning upon adetermination that the patient is not connected to the medical pump. 29.The method of claim 27, wherein the authenticating a command comprises:generating a random number; encoding said random number into a signal;broadcasting the signal into the patient through a fluid deliverydevice; delivering said random number to a communication unit;communicating at least one command and said random number to saidmedical pump from said communication unit; and confirming saidcommunication unit communicated said random number.
 30. The method ofclaim 29, wherein authenticating said command further comprisesoutputting an error condition if said medical pump does not receive saidrandom number.
 31. A system for infusing fluid, said system comprising:a pumping mechanism configured to pump fluid; a first electric fieldsensor configured to estimate a first electric field associated with apatient; a second electric field sensor configured to estimate a secondelectric field associated with said patient, wherein said first andsecond electric field sensors are configured to be operatively coupledto a fluid path of said pumping mechanism; and a measurement componentconfigured to measure differences between said first electric field andsaid second electric field.
 32. A pump for infusing fluid, said pumpcomprising: a pumping mechanism configured to pump fluid; a means formeasuring a first electric field associated with a patient; a means formeasuring a second electric field associated with said patient, whereinsaid means for measuring a first electric field and means for measuringa second electric field are configured to be operatively coupled to afluid path of said pumping mechanism; and a means for measuringdifferences between said first electric field and second electric field.33. A pump infusing fluid, said pump comprising: a pumping mechanismconfigured to pump fluid; a first electric field sensor configured toestimate a first electric field associated with a patient; a secondelectric field sensor configured to estimate a second electric fieldassociated with said patient, wherein said first and second electricfield sensors are configured to be operatively coupled to a fluid pathof said pumping mechanism; and a measurement circuit configured tomeasure differences between said first electric field associated withsaid patient and said second electric field associated with saidpatient.